Fluid jet print head and method of terminating operation thereof

Abstract

A fluid jet print head includes a manifold defining a fluid receiving reservoir and at least one orifice communicating with the reservoir. An inflation means cooperates with the manifold and expands within the reservoir to displace fluid from the reservoir. The inflation means contacts the manifold, thus sealing the orifice and terminating fluid flow through the orifice. In a first embodiment, the inflatable means includes an elastic diaphragm which may be inflated to extend into the reservoir. In a second embodiment, the inflatable means includes an elastic tube, sealed at a first end thereof and extending into the reservoir. When pressurized air is applied to the interior of the tube, the tube expands, filling the reservoir and sealing the orifices.

What is claimed is: 
     
       1. A fluid jet print head, comprising: manifold means defining a fluid receiving reservoir, a fluid inlet communicating with said fluid reservoir, and at least one orifice communicating with said fluid reservoir,   means for supplying fluid through said fluid inlet to said fluid reservoir to produce a jet drop stream emanating from said orifice, and   inflatable means, cooperating with said manifold means, for expansion within said fluid reservoir to displace fluid therefrom and contact said manifold means so as to seal said orifice and terminate fluid flow through said orifice.   
     
     
       2. The fluid jet print head of claim 1 in which said inflatable means comprises an elastic diaphragm mounted within said manifold means and extending across said fluid receiving reservoir so as to form one wall of said reservoir, opposite said orifice. 
     
     
       3. The fluid jet print head of claim 2 in which said elastic diaphragm is made of neoprene. 
     
     
       4. The fluid jet print head of claim 2 in which said elastic diaphragm is made of silicone rubber. 
     
     
       5. The fluid jet print head of claim 2 in which said manifold means defines a plurality of orifices, arranged in at least one row, for producing a plurality of jet drop streams, and in which said elastic diaphragm may contact said manifold means so as to terminate fluid flow through said plurality of orifices. 
     
     
       6. The fluid jet print head of claim 2 in which said manifold means further defines an inflation chamber on the side of said elastic diaphragm opposite said fluid receiving reservoir, and   an air inlet, communicating with said inflation chamber, for supplying air to said inflation chamber at a pressure sufficient to expand said elastic diaphragm into said reservoir.   
     
     
       7. The fluid jet print head of claim 6 in which said manifold means comprises an upper manifold portion defining said inflation chamber, a lower manifold portion including an orifice plate defining said fluid receiving reservoir, and means for securing together said upper manifold portion and said lower manifold portion with said elastic diaphragm compressed at its periphery therebetween, whereby said elastic diaphragm provides a fluid seal between said inflation chamber and said reservoir and, additionally, acts as a gasket between said upper manifold portion and said lower manifold portion. 
     
     
       8. The fluid jet print head of claim 6 in which said means for supplying fluid through said fluid inlet provides fluid at a first predetermined pressure and, further, comprising means for supplying air to said air inlet at a second predetermined pressure, said second predetermined pressure being greater than said first predetermined pressure. 
     
     
       9. The fluid jet print head of claim 6 further comprising stimulator means, mounted in said inflation chamber in contact with said elastic diaphragm, for applying mechanical stimulation to said fluid in said reservoir through said diaphragm, whereby pressure waves pass through said fluid and produce uniform break up of drops in said jet drop stream. 
     
     
       10. The fluid jet print head of claim 9 in which said stimulator means comprises at least one piezoelectric transducer. 
     
     
       11. The fluid jet print head of claim 1 in which said inflatable means comprises an elastic tube, sealed at a first end thereof, extending into said fluid receiving reservoir such that said first end of said elastic tube is on the opposite side of said orifice from said fluid inlet. 
     
     
       12. The fluid jet print head of claim 11 further comprising means, connected to the end of said elastic tube opposite said first end thereof, for applying pressured air to said elastic tube to cause inflation of said tube and sealing of said orifices, and for applying a partial vacuum to said tube to evacuate the interior of said tube and fully collapse said tube. 
     
     
       13. The fluid jet print head of claim 11 in which said elastic tube is made of surgical rubber. 
     
     
       14. The fluid jet print head of claim 11 in which said means for supplying fluid through said fluid inlet provides fluid at a first predetermined pressure and, further, comprising means, connected to said end of said elastic tube opposite said first end thereof, for supplying air to the interior of said tube at a second predetermined pressure, said second predetermined pressure being greater than said first predetermined pressure. 
     
     
       15. The fluid jet print head of claim 11 in which said elastic tube extends through said fluid inlet into said fluid receiving reservoir. 
     
     
       16. The fluid jet print head of claim 15 in which said manifold means further defines a plurality of orifices arranged in at least one row, and in which said elastic tube extends from said fluid inlet past all of said plurality of orifices, whereby inflation of said elastic tube seal all of said plurality of orifices. 
     
     
       17. The fluid jet print head of claim 16 in which said manifold means includes an orifice plate defining said plurality of orifices and, further, comprising stimulator means mounted on said manifold means in contact with said orifice plate at a point on the opposite side of said first end of said elastic tube from the fluid inlet for applying mechanical stimulation to said orifice plate, whereby traveling waves pass along said orifice plate and produce uniform drop break up of the jet drop streams emanating from said orifices. 
     
     
       18. A fluid jet print head, comprising: manifold means defining a fluid receiving reservoir, a fluid inlet communicating with said reservoir, and a plurality of orifices communicating with said fluid receiving reservoir,   means for supplying fluid through said fluid inlet to said reservoir to produce a plurality of jet drop streams emanating from said orifices, and   sealing means within said print head means for movement within said reservoir into sealing contact with said manifold means around each of said orifices, whereby said orifices are sealed and fluid flow therethrough is terminated.   
     
     
       19. The fluid jet print head of claim 18 in which said sealing means comprises inflatable means for expansion within said reservoir to displace fluid therefrom and contact said manifold means so as to seal said orifices. 
     
     
       20. The fluid jet print head of claim 19 in which said inflatable means comprises an elastic diaphragm mounted in said manifold means and extending across said fluid receiving reservoir so as to form one wall of said reservoir, opposite said orifices. 
     
     
       21. The fluid jet printer of claim 19 in which said inflatable means comprises an elastic tube sealed at a first end thereof and extending into said fluid receiving reservoir. 
     
     
       22. In a fluid jet print head having a manifold means defining a fluid receiving reservoir, a fluid inlet communicating with said fluid reservoir, and at least one orifice communicating with said fluid reservoir, and means for supplying fluid through said fluid inlet to said reservoir to produce a jet drop stream emanating from said orifice, the method of terminating production of said jet drop stream, comprising the steps of: substantially reducing the volume of said fluid reservoir by movement of a sealing means therein, and   bringing said sealing means into contact with said manifold means so as to seal said orifice.   
     
     
       23. The method of claim 22 in which said sealing means defines a wall of said fluid reservoir opposite said orifice, and in which the step of substantially reducing the volume of said fluid reservoir includes the step of: moving said sealing means toward said orifice until said sealing means contacts said manifold means.   
     
     
       24. The method of claim 22 in which said sealing means comprises an inflatable tube positioned within said fluid reservoir, and in which the step of substantially reducing the volume of said fluid reservoir includes the step of: inflating said tube until said tube contacts said manifold means.